Swimming is great exercise not just for you but also for your dog. A great think about hiking is that when you go hiking you often find amazing lakes to go swimming in. This is an amazing way to cool off after a hot hiking trail for both you and your dog.
When you do hiking and expect to end up going in a river or lake and are taking your puppy it is critical to think about the dog safety devices available to you. Some dogs are natural swimmers. However there are many dogs that are not good swimmers. Even if your dog is an amazing swimming the waters you find when hiking can have strong currents or otherwise be unpredictable. Even a dog who is a good swimmer may need swim safety gear.
One piece of equipment to consider is a personal floatation device. These are available in different sizes and levels of durability and buoyancy. Other equipment and products to consider is shampoo to clean the dog after the swim and toys. There is a multitude of toys that are buoyant to make the swim more fun for everyone.